How to make email permission required when logging in/signing up a user using the FB login?
You should check the received Access Token before you continue with your application logic. How to do this is described here:
https://developers.facebook.com/docs/facebook-login/permissions/v2.0#checking
If you then recognize that the User didn't give the email permission, you can resend him to the permission dialog as described here:
https://developers.facebook.com/docs/facebook-login/permissions/v2.0#handling
Quote:
If someone has declined a permission for your app, the login dialog won't let your app re-request the permission unless you pass
auth_type=rerequestalong with your request.
using facebook php sdk
require_once 'facebook-sdk/facebook.php';$config = array ( 'appId' => 'your id', 'secret' => 'your secret', 'fileUpload' => false, 'allowSignedRequest' => false);$facebook = new Facebook ( $config );$fb_user_id = $facebook->getUser ();$fb_params = array ( 'scope' => 'email, publish_stream');and generate login url for your users
if (empty ( $fb_user_id )) { $fb_login_url = $facebook->getLoginUrl ( $fb_params );}